In this study, heating and cooling day data were calculated by employing the degree-day method using long-term climate data belonging to Isparta (Turkey) and its districts, and the inside temperature recommended for broiler chickens. The recommended inside temperatures during a raising period of broiler chickens were chosen as equilibrium temperature. Heating Degree Day (HDD), Cooling Degree Day (CDD), Heating Degree Day Number (HDDN) and Cooling Degree Day Number (CDDN) were calculated by the equations given in the study using long-term temperature records of 16 stations obtained from the General Directorate of State Meteorology Works for Isparta and its districts. It was determined that the HDD number is higher than the number of CDD in almost all raising periods in Isparta and its districts. Therefore, the inside temperature recommended for broiler chickens, i.e. the equilibrium temperature, increases when the HDD values also increase. As a conclusion it is considered that more proper conditions for the animals in the house can be provided and the enterprise can be operated economically by taking obtained heating and cooling day data into account in the project design stage.